This invention concerns conveyor belts and chains, and processes employing conveyor belts, and more particularly the invention is directed to a conveyor chain of molded plastic material, with special chain links at spaced locations, fashioned similar to the normal links but with provision for stably supporting an upright member that supports apparatus for holding poultry in a production line in which the poultry is deboned or otherwise processed.
Chicken processing conveyors and deboning conveyors are shown in U.S. Pat. Nos. 4,385,419, 5,535,876, 4,716,624, 5,080,630, 6,283,847 and 6,688,461. See also U.S. Pat. Nos. 1,749,224 and 5,083,974.
As shown in many of the above-listed patents, what is needed in such a poultry processing line is typically a rigid upright stud which might carry a cone-shaped poultry carcass supporting device. Such a processing line is often called a “cone line”. Typically the upright stud is a stainless steel rod. In U.S. Pat. No. 6,283,847 such studs are provided on a belt of metal plates. In U.S. Pat. No. 4,716,624 the studs are again welded to metal chain links. In U.S. Pat. No. 4,385,419 another arrangement is shown with metal cone-supporting studs extending up from metal chain links, welded or bolted to the metal links. Side tracks are provided to engage with the chain links to prevent lateral tipping of the chain while a chicken is deboned.
In U.S. Pat. No. 6,688,461, studs are shown connected to a plastic or steel chain, but by means of special mounting blocks at spaced locations which fit over and mount onto links of the chain, as attachments. U.S. Pat. No. 5,535,876 shows another arrangement whereby a chain comprised of a series of linked modules, and capable of traveling around gentle curves, includes a special link at spaced locations (e.g. about every fifth link), these special links being machined blocks with threaded holes to receive an upright stud, each block taking the place of a normal link in the chain.
There has been a need for an efficiently and economically produced chain link for a plastic conveyor chain, providing a stable support for a threaded upright stud for poultry processing.
According to the current invention, such a chain link is integrally injection molded and is similar in substantially all respects to a normal link of a modular molded plastic conveyor chain in a lower portion of the special link, but with an efficient upper structure of the link to support a rod or stud for use in poultry processing, in an upwardly-extending threaded boss. The special stud-supporting links are made to fit directly as substitutes for links in thermoplastic chain conveyors for the food industry such as, for example, N12000 thermoplastic chain, 2″ pitch, manufactured by KVP Falcon Plastic Belting, Inc. of Reading, Pa., either straight-travel chain or radius chain. These chains are typically made of food grade and temperature-insensitive materials such as propylene and acetal, and the stud-supporting links may be made of the same materials.
The poultry processing plastic chain link of the invention has distinct advantages over prior poultry processing links, in strength, weight and efficiency of manufacture. The lower or base portion of the link is essentially the same as the other links of the chain within which the special link fits. It is integrally molded, preferably injection molded, made with a minimum of plastic material. A pair of stabilizing flanges or ledges extend laterally outwardly just above the base portion, and extending upwardly from the platform defining these ledges is a female-threaded boss that receives the threaded rod for a chicken-holding cone or other structure used in poultry processing. The threaded boss is formed with minimal plastic material, essentially a threaded cylinder, a relatively light mass of material, but with a series of buttresses or ribs on the outside of the cylinder, stabilizing the threaded cylinder on the platform. This construction achieves minimal weight and efficiency in production, as compared to a prior art plastic device which was machined and consisted of a very heavy block of material that had a threaded hole extending down into that block of material.
Accordingly, it is an object of the invention to improve the cost efficiency, strength, weight, convenience of assembly and operation, and performance capability in a stud-supporting conveyor chain, particularly for supporting poultry for manual operations, with an injection molded thermoplastic chain link which has a lower portion conforming substantially precisely to the size and shape of other chain links in the chain, and an upper portion that has stabilizing edges and a strong and rigidly supported screw thread for receiving a threaded stud rod to extend upwardly. These and other objects, advantages and features of the invention will be apparent from the following description of a preferred embodiment, considered along with the accompanying drawings.